Blaze example of "Helper calculates which template to display, passing a data context to the template" doesn't actually work.

[tmeasday]

Number 2. from here: https://github.com/meteor/meteor/wiki/Using-Blaze#templatefoo-is-not-a-function-and-does-not-return-a-string

Reproduction: https://github.com/tmeasday/blaze-example-wrong

In Template.foo.post, this is set to the result of Template.foo.postData. You could work around this by setting Template.foo.postData = {foo: 'bar', postName: this.postName}.

Kind of crappy though, as most times postData would come from a collection.

[estark37]

Hey @tmeasday -- excellent point, thanks! We're fixing this by replacing these examples with

{{> UI.dynamic template=foo data=bar}}

(where foo can be a helper that calculates the name of the template to display, and bar calculates the data context with which to render the subtemplate).

This will be on devel soon and out in the next release, at which point we'll update the wiki.

[philcockfield]

This looks great @estark37

[tmeasday]

That seems like an ideal solution @estark37

[estark37]

Glad to hear it -- @avital's idea :)

[mizzao]

Woot! This also fixes https://groups.google.com/forum/#!topic/meteor-talk/Hfrr0_xHv4g.

[estark37]

{{> UI.dynamic}} is out in 0.8.2, and I've updated the wiki (though the wording is still in flux). Thanks @tmeasday!

[mizzao]

I just spent half an hour figuring out that the helper passed in for the template argument requires "foo" rather than Template.foo. When using the latter, nothing at all is rendered. Especially confusing as {{> someTemplate}} where someTemplate is a helper expects Template.foo to be returned.

It would be great to make a note of this somewhere or maybe just support both depending on whether a string or a template component is passed in.

It also appears that UI._parentData(n) doesn't 'reach up' through UI.dynamic. Is it meant to be this way? I'm going to hop on devel for now and see if it's the same case with blaze-refactor.

[avital]

Sure, we'll look at a pull request (with tests) letting UI.dynamic accept templates in addition to template names.

UI._parentData should do the exact same thing as ... So if you're right, I'd like to know whether .. behaves the right way or not. If you think there's a bug please file a new ticket.

[mizzao]

Hi @avital, I discovered that this was actually due to a slightly different problem. See #2337.